The volume package does not test enough use-cases.
Improve test coverage by adding additional tests and refactoring
current tests to use table testing.
This change introduces a new error var to make testing unsupported
volume type errors easier.
This change does not introduce any changes in behavior.
Adds EmptyDirectory to volumes. This represents a directory
on the host, given to a pod that should not persist beyond.
The current draft does not cleanup after itself.
Adds the framework for external volume mounts.
Currently supports bare host directory mounts.
Modifies the API to support host directory mounts from Volumes
instead of VolumeMounts.